RE: [PATCH v5 5/7] drm/aspeed: Add reset and clock for AST2600

Tommy Huang
2022-03-02T00:04:40Z

Hi Joel,

> -----Original Message-----
> From: Joel Stanley <joel@jms.id.au>
> Sent: Tuesday, March 1, 2022 7:05 PM
> To: Tommy Huang <tommy_huang@aspeedtech.com>
> Cc: David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; Rob
> Herring <robh+dt@kernel.org>; Andrew Jeffery <andrew@aj.id.au>;
> linux-aspeed <linux-aspeed@lists.ozlabs.org>; open list:DRM DRIVERS
> <dri-devel@lists.freedesktop.org>; devicetree <devicetree@vger.kernel.org>;
> Linux ARM <linux-arm-kernel@lists.infradead.org>; Linux Kernel Mailing List
> <linux-kernel@vger.kernel.org>; BMC-SW <BMC-SW@aspeedtech.com>
> Subject: Re: [PATCH v5 5/7] drm/aspeed: Add reset and clock for AST2600
>
> On Tue, 1 Mar 2022 at 07:00, Tommy Huang
> <tommy_huang@aspeedtech.com> wrote:
> >
> > Hi Joel,
> >
> > It seems that the reset control could keep original code behavior.
> > Just change the reset define in the .dtsi file from
> ASPEED_RESET_CRT1 into ASPEED_RESET_GRAPHICS.
>
> Right, because the ASPEED_RESET_CRT reset is released by the
> ASPEED_CLK_GATE_D1CLK line?
>
> include/dt-bindings/clock/ast2600-clock.h:#define ASPEED_RESET_CRT
> 13
>
> drivers/clk/clk-ast2600.c: /*
> clk rst name parent flags */
> drivers/clk/clk-ast2600.c: [ASPEED_CLK_GATE_D1CLK] = {
> 10, 13, "d1clk-gate", "d1clk", 0 >
>
>
>
> >
> > By the way, the HW controller states and FW programming register
> will be reset by CRT reset line.
> > And another part HW controller states will be reset by engine
> reset line.
>
> Thanks. Can we include that in the commit message for the device tree
> change?
>

Got it. I will add this and re-send the patches.
Thanks for your suggestion.

> >
> > Thanks,
> >
> > By Tommy
> >
> > > -----Original Message-----
> > > From: Joel Stanley <joel@jms.id.au>
> > > Sent: Monday, February 28, 2022 5:51 PM
> > > To: Tommy Huang <tommy_huang@aspeedtech.com>
> > > Cc: David Airlie <airlied@linux.ie>; Daniel Vetter
> > > <daniel@ffwll.ch>; Rob Herring <robh+dt@kernel.org>; Andrew Jeffery
> > > <andrew@aj.id.au>; linux-aspeed <linux-aspeed@lists.ozlabs.org>;
> > > open list:DRM DRIVERS <dri-devel@lists.freedesktop.org>; devicetree
> > > <devicetree@vger.kernel.org>; Linux ARM
> > > <linux-arm-kernel@lists.infradead.org>; Linux Kernel Mailing List
> > > <linux-kernel@vger.kernel.org>; BMC-SW <BMC-SW@aspeedtech.com>
> > > Subject: Re: [PATCH v5 5/7] drm/aspeed: Add reset and clock for
> > > AST2600
> > >
> > > On Wed, 8 Dec 2021 at 01:34, Tommy Haung
> > > <tommy_huang@aspeedtech.com> wrote:
> > > >
> > > > From: tommy-huang <tommy_huang@aspeedtech.com>
> > > >
> > > > Add more reset and clock select code for AST2600.
> > > > The gfx_flags parameter was added for chip caps idenified.
> > >
> > > Can you tell me a bit more about the two reset lines:
> > >
> > > What is the CRT reset line controlling?
> > >
> > > What does the engine reset line control?
> > >
> > > Can we use devm_reset_control_array_get() to get whichever are
> > > specified in the device tree, so we don't need to have different
> > > logic for the 2600 and earlier chips?
> > >
> > >
> > >
> > > >
> > > > Signed-off-by: tommy-huang <tommy_huang@aspeedtech.com>
> > > > ---
> > > > drivers/gpu/drm/aspeed/aspeed_gfx.h | 16 +++++++-
> > > > drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c | 16 ++++++++
> > > > drivers/gpu/drm/aspeed/aspeed_gfx_drv.c | 50
> > > ++++++++++++++++++++++--
> > > > 3 files changed, 77 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > index 4e6a442c3886..2c733225d3c7 100644
> > > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > @@ -8,7 +8,8 @@ struct aspeed_gfx {
> > > > struct drm_device drm;
> > > > void __iomem *base;
> > > > struct clk *clk;
> > > > - struct reset_control *rst;
> > > > + struct reset_control *rst_crt;
> > > > + struct reset_control *rst_engine;
> > > > struct regmap *scu;
> > > >
> > > > u32 dac_reg;
> > > > @@ -16,6 +17,7 @@ struct aspeed_gfx {
> > > > u32 vga_scratch_reg;
> > > > u32 throd_val;
> > > > u32 scan_line_max;
> > > > + u32 flags;
> > > >
> > > > struct drm_simple_display_pipe pipe;
> > > > struct drm_connector connector;
> > > > @@ -106,3 +108,15 @@ int aspeed_gfx_create_output(struct
> > > > drm_device *drm);
> > > > /* CRT_THROD */
> > > > #define CRT_THROD_LOW(x) (x)
> > > > #define CRT_THROD_HIGH(x) ((x) << 8)
> > > > +
> > > > +/* SCU control */
> > > > +#define SCU_G6_CLK_COURCE 0x300
> > > > +
> > > > +/* GFX FLAGS */
> > > > +#define RESET_MASK BIT(0)
> > > > +#define RESET_G6 BIT(0)
> > > > +#define CLK_MASK BIT(4)
> > > > +#define CLK_G6 BIT(4)
> > > > +
> > > > +#define G6_CLK_MASK (BIT(8) | BIT(9) | BIT(10))
> > > > +#define G6_USB_40_CLK BIT(9)
> > > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > > b/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > > index 827e62c1daba..e0975ecda92d 100644
> > > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > > @@ -77,6 +77,18 @@ static void
> > > > aspeed_gfx_disable_controller(struct
> > > aspeed_gfx *priv)
> > > > regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), 0);
> > > > }
> > > >
> > > > +static void aspeed_gfx_set_clk(struct aspeed_gfx *priv) {
> > > > + switch (priv->flags & CLK_MASK) {
> > > > + case CLK_G6:
> > > > + regmap_update_bits(priv->scu,
> SCU_G6_CLK_COURCE,
> > > G6_CLK_MASK, 0x0);
> > > > + regmap_update_bits(priv->scu,
> SCU_G6_CLK_COURCE,
> > > G6_CLK_MASK, G6_USB_40_CLK);
> > > > + break;
> > > > + default:
> > > > + break;
> > > > + }
> > > > +}
> > > > +
> > > > static void aspeed_gfx_crtc_mode_set_nofb(struct aspeed_gfx *priv)
> {
> > > > struct drm_display_mode *m =
> > > > &priv->pipe.crtc.state->adjusted_mode;
> > > > @@ -87,6 +99,8 @@ static void aspeed_gfx_crtc_mode_set_nofb(struct
> > > aspeed_gfx *priv)
> > > > if (err)
> > > > return;
> > > >
> > > > + aspeed_gfx_set_clk(priv);
> > > > +
> > > > #if 0
> > > > /* TODO: we have only been able to test with the 40MHz USB
> > > clock. The
> > > > * clock is fixed, so we cannot adjust it here. */ @@
> > > > -193,6
> > > > +207,7 @@ static void aspeed_gfx_pipe_update(struct
> > > > drm_simple_display_pipe *pipe, static int
> > > > aspeed_gfx_enable_vblank(struct drm_simple_display_pipe *pipe) {
> > > > struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
> > > > +
> > > > u32 reg = readl(priv->base + CRT_CTRL1);
> > > >
> > > > /* Clear pending VBLANK IRQ */ @@ -207,6 +222,7 @@ static
> > > > int aspeed_gfx_enable_vblank(struct drm_simple_display_pipe *pipe)
> > > > static void aspeed_gfx_disable_vblank(struct
> > > > drm_simple_display_pipe *pipe) {
> > > > struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
> > > > +
> > > > u32 reg = readl(priv->base + CRT_CTRL1);
> > > >
> > > > reg &= ~CRT_CTRL_VERTICAL_INTR_EN; diff --git
> > > > a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > > b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > > index d10246b1d1c2..59a0de92650f 100644
> > > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > > @@ -64,6 +64,7 @@ struct aspeed_gfx_config {
> > > > u32 vga_scratch_reg; /* VGA scratch register in SCU */
> > > > u32 throd_val; /* Default Threshold Seting */
> > > > u32 scan_line_max; /* Max memory size of one scan
> line */
> > > > + u32 gfx_flags; /* Flags for gfx chip caps */
> > > > };
> > > >
> > > > static const struct aspeed_gfx_config ast2400_config = { @@ -72,6
> > > > +73,7 @@ static const struct aspeed_gfx_config ast2400_config = {
> > > > .vga_scratch_reg = 0x50,
> > > > .throd_val = CRT_THROD_LOW(0x1e) |
> CRT_THROD_HIGH(0x12),
> > > > .scan_line_max = 64,
> > > > + .gfx_flags = 0,
> > > > };
> > > >
> > > > static const struct aspeed_gfx_config ast2500_config = { @@ -80,6
> > > > +82,7 @@ static const struct aspeed_gfx_config ast2500_config = {
> > > > .vga_scratch_reg = 0x50,
> > > > .throd_val = CRT_THROD_LOW(0x24) |
> CRT_THROD_HIGH(0x3c),
> > > > .scan_line_max = 128,
> > > > + .gfx_flags = 0,
> > > > };
> > > >
> > > > static const struct aspeed_gfx_config ast2600_config = { @@ -88,6
> > > > +91,7 @@ static const struct aspeed_gfx_config ast2600_config = {
> > > > .vga_scratch_reg = 0x50,
> > > > .throd_val = CRT_THROD_LOW(0x50) |
> CRT_THROD_HIGH(0x70),
> > > > .scan_line_max = 128,
> > > > + .gfx_flags = RESET_G6 | CLK_G6,
> > > > };
> > > >
> > > > static const struct of_device_id aspeed_gfx_match[] = { @@ -138,6
> > > > +142,44 @@ static irqreturn_t aspeed_gfx_irq_handler(int irq, void
> > > > +*data)
> > > > return IRQ_NONE;
> > > > }
> > > >
> > > > +static int aspeed_gfx_reset(struct drm_device *drm) {
> > > > + struct platform_device *pdev = to_platform_device(drm->dev);
> > > > + struct aspeed_gfx *priv = to_aspeed_gfx(drm);
> > > > +
> > > > + switch (priv->flags & RESET_MASK) {
> > > > + case RESET_G6:
> > > > + priv->rst_crt = devm_reset_control_get(&pdev->dev,
> > > "crt");
> > > > + if (IS_ERR(priv->rst_crt)) {
> > > > + dev_err(&pdev->dev,
> > > > + "missing or invalid crt reset
> > > > + controller
> > > device tree entry");
> > > > + return PTR_ERR(priv->rst_crt);
> > > > + }
> > > > + reset_control_deassert(priv->rst_crt);
> > > > +
> > > > + priv->rst_engine =
> > > > + devm_reset_control_get(&pdev->dev,
> > > "engine");
> > > > + if (IS_ERR(priv->rst_engine)) {
> > > > + dev_err(&pdev->dev,
> > > > + "missing or invalid engine reset
> > > controller device tree entry");
> > > > + return PTR_ERR(priv->rst_engine);
> > > > + }
> > > > + reset_control_deassert(priv->rst_engine);
> > > > + break;
> > > > +
> > > > + default:
> > > > + priv->rst_crt =
> > > devm_reset_control_get_exclusive(&pdev->dev, NULL);
> > > > + if (IS_ERR(priv->rst_crt)) {
> > > > + dev_err(&pdev->dev,
> > > > + "missing or invalid reset
> > > > + controller
> > > device tree entry");
> > > > + return PTR_ERR(priv->rst_crt);
> > > > + }
> > > > + reset_control_deassert(priv->rst_crt);
> > > > + break;
> > > > + }
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > static int aspeed_gfx_load(struct drm_device *drm) {
> > > > struct platform_device *pdev =
> > > > to_platform_device(drm->dev); @@ -163,6 +205,7 @@ static int
> aspeed_gfx_load(struct drm_device *drm)
> > > > priv->vga_scratch_reg = config->vga_scratch_reg;
> > > > priv->throd_val = config->throd_val;
> > > > priv->scan_line_max = config->scan_line_max;
> > > > + priv->flags = config->gfx_flags;
> > > >
> > > > priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon");
> > > > if (IS_ERR(priv->scu)) {
> > > > @@ -186,13 +229,12 @@ static int aspeed_gfx_load(struct drm_device
> > > *drm)
> > > > return ret;
> > > > }
> > > >
> > > > - priv->rst = devm_reset_control_get_exclusive(&pdev->dev,
> NULL);
> > > > - if (IS_ERR(priv->rst)) {
> > > > + ret = aspeed_gfx_reset(drm);
> > > > + if (ret) {
> > > > dev_err(&pdev->dev,
> > > > "missing or invalid reset controller
> > > > device tree
> > > entry");
> > > > - return PTR_ERR(priv->rst);
> > > > + return ret;
> > > > }
> > > > - reset_control_deassert(priv->rst);
> > > >
> > > > priv->clk = devm_clk_get(drm->dev, NULL);
> > > > if (IS_ERR(priv->clk)) {
> > > > --
> > > > 2.17.1
> > > >